Preparation method of high-toughness titanium alloy frame reinforced magnesium-based composite material

Abstract

The invention belongs to the field of metal composite materials, and particularly discloses a preparation method of a high-toughness titanium alloy frame reinforced magnesium-based composite material, and the preparation method comprises the following steps: arranging and fixing titanium alloy wires in a mold to obtain a titanium alloy frame; then magnesium alloy is injected into the titanium alloy frame, compression molding is conducted after vibration, and a composite material blank is obtained; and sintering the composite material green body to prepare the magnesium-based composite material. The magnesium-based composite material prepared through the preparation method is reinforced through the titanium alloy frame, the titanium alloy frame and the magnesium alloy have a good bonding interface and have high mechanical performance and low density, specifically, the yield strength is larger than or equal to 500 MPa, the tensile strength is larger than or equal to 500 MPa, the elastic modulus is larger than or equal to 80 GPa, the density is smaller than or equal to 3.2 g / cm < 3 >, and the problem that existing magnesium alloy is poor in strength is remarkably solved.

Description

Technical Field

[0001] The present invention belongs to the field of metal composite materials, and particularly relates to a preparation method of a high-strength and tough titanium alloy frame-reinforced magnesium matrix composite material. Background Art

[0002] As a new generation of lightweight structural materials, magnesium matrix composites have attracted wide attention in the field of engineering applications. Due to their characteristics such as lightweight, high specific stiffness, high specific strength, and abundant resources, they have gradually become the most promising light metal materials after steel and aluminum alloys.

[0003] Due to its low density, excellent comprehensive mechanical properties, and abundant reserves, metallic magnesium is expected to become a new generation of materials for aerospace and military equipment. However, its poor strength and plasticity have hindered its wide application in related fields. Therefore, it is particularly important to prepare magnesium matrix composites with high strength and toughness. Summary of the Invention

[0004] In order to overcome at least one of the above-mentioned technical problems existing in the prior art, one of the purposes of the present invention is to provide a magnesium matrix composite material.

[0005] Another purpose of the present invention is to provide a preparation method of a magnesium matrix composite material.

[0006] Another purpose of the present invention is to provide the application of the above-mentioned magnesium matrix composite material in the fields of transportation equipment, marine engineering equipment, building materials, or electronic equipment.

[0007] In order to achieve the above purposes, the technical solutions adopted by the present invention are as follows:

[0008] The first aspect of the present invention provides a magnesium matrix composite material, comprising the following preparation raw materials in volume percentages: 45-50% of a titanium alloy frame; 50-55% of a magnesium alloy; the titanium alloy frame is composed of at least two titanium alloy wires arranged.

[0009] The present invention controls the density of the magnesium matrix composite material by limiting the content of the titanium alloy frame and ensuring the volume percentage of the magnesium alloy.

[0010] In some embodiments of the present invention, the volume percentage of the titanium alloy frame is selected from any value or any range value formed by any two of 45%, 45.5%, 46%, 46.5%, 47%, 47.5%, 48%, 48.5%, 49%, 49.5%, 50%.

[0011] In some embodiments of the present invention, the volume percentage of the magnesium alloy is selected from any value among 50%, 50.5%, 51%, 51.5%, 52%, 52.5%, 53%, 53.5%, 54%, 54.5%, 55% or a range value formed by any two of them.

[0012] In some embodiments of the present invention, the spacing between two adjacent titanium alloy wires is 0.75 mm - 5 mm; in some embodiments of the present invention, the spacing between two adjacent titanium alloy wires is any value among 0.75 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm or a range value formed by any two of them.

[0013] In some embodiments of the present invention, the arrangement mode is selected from at least one of unidirectional parallel arrangement, orthogonal laminated arrangement, skew arrangement, and braided structure arrangement. The titanium alloy wires can be arranged and combined into a titanium alloy frame by at least one of unidirectional parallel arrangement, orthogonal laminated arrangement, skew arrangement, and braided structure arrangement.

[0014] In some embodiments of the present invention, the diameter of the titanium alloy wire is 0.5 mm - 3.5 mm; in some embodiments of the present invention, the diameter of the titanium alloy wire is any value among 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm or a range value formed by any two of them. The design of the diameter of the titanium alloy wire is to meet the sintering requirements of the titanium alloy frame. If the titanium alloy wire is too thin, the interfacial reaction during the sintering process will cause the titanium alloy wire to disappear and unable to provide strength. If the titanium alloy wire is too thick, cracks are likely to appear after sintering, and the interfacial bonding strength is poor, affecting the strength of the magnesium matrix composite material.

[0015] In some embodiments of the present invention, the material of the titanium alloy wire is selected from at least one of TC4, TC6, TC11, Ti1023, TA12, TA7, TA11.

[0016] In some embodiments of the present invention, the magnesium alloy includes at least one of Mg-Al series alloy, Mg-Zn series alloy, Mg-Mn series alloy, and Mg-RE series alloy.

[0017] In some embodiments of the present invention, the Mg-Al series alloy includes at least one of AZ91D alloy, AZ31 alloy, AZ61 alloy, AM50 alloy, AM60 alloy, and AE42 alloy.

[0018] In some embodiments of the present invention, the Mg-Zn series alloy includes at least one of ZK60 alloy, ZK30 alloy, ZE41 alloy, ZE63 alloy, Mg-Zn-Ca alloy, and Mg-Zn-Y alloy.

[0019] In some embodiments of the present invention, the Mg-Mn series alloy includes at least one of M1A alloy, M2M alloy, ME20M alloy, Mg-Mn-Ca alloy, and Mg-Mn-Zr alloy.

[0020] In some embodiments of the present invention, the Mg-RE series alloy (RE refers to rare earth elements) includes at least one of WE43 alloy, WE54 alloy, EK60 alloy, Mg-Zn-Zr alloy, and Mg-Y-Nd-Zr alloy.

[0021] In some embodiments of the present invention, the particle size of the magnesium alloy is 10 - 100 μm; in some embodiments of the present invention, the particle size of the magnesium alloy is any value among 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm or the range value formed by any two of them. If the particle size of the magnesium alloy powder is too small, the oxidation of the powder intensifies, the ablation during the sintering process is serious, and at the same time, the safety during powder filling is poor and it is easy to burn.

[0022] In some embodiments of the present invention, the magnesium alloy is spherical or quasi-spherical. The sphericity is to provide the powder fluidity of the magnesium alloy, which is easier to fill the pore positions of the titanium alloy frame, and at the same time increase the density of the titanium alloy frame.

[0023] In some embodiments of the present invention, the yield strength of the magnesium-based alloy material ≥ 500 MPa; in some embodiments of the present invention, the yield strength of the magnesium-based alloy material is 510 - 530 MPa.

[0024] In some embodiments of the present invention, the tensile strength of the magnesium-based alloy material ≥ 500 MPa; in some embodiments of the present invention, the tensile strength of the magnesium-based alloy material is 540 - 580 MPa.

[0025] In some embodiments of the present invention, the elastic modulus of the magnesium-based alloy material ≥ 80 GPa.

[0026] In some embodiments of the present invention, the density of the magnesium-based alloy material is ≤ 3.2 g / cm 3 .

[0027] The second aspect of the present invention provides a method for preparing the magnesium-based composite material described in the first aspect of the present invention, comprising the following steps:

[0028] Arrange and fix the titanium alloy wire in a mold to obtain a titanium alloy frame;

[0029] Then inject magnesium alloy into the titanium alloy frame, vibrate and press it into shape to obtain a composite material blank;

[0030] Sinter the composite material blank to obtain the magnesium-based composite material.

[0031] In some embodiments of the present invention, the step of arranging and fixing the titanium alloy wire in the mold is specifically: inserting the titanium alloy wire into the circular hole array arranged in the mold so as to form a titanium alloy frame in the mold.

[0032] The present invention uses a mold to fix the position of the titanium alloy wire, thereby controlling the shape of the titanium alloy frame, and then providing an environment for the magnesium alloy powder to be filled into the titanium alloy frame, cold pressed and sintered for densification.

[0033] In some embodiments of the present invention, the circular hole array is formed by arranging circular holes with a hole diameter of 0.5 - 3.5 mm at a distance of 0.75 mm - 5 mm.

[0034] In some embodiments of the present invention, a feeding hole is provided at the top of the mold, and the aperture of the feeding hole is 30 - 50 mm. The magnesium alloy is added into the titanium alloy frame through the feeding hole.

[0035] In some embodiments of the present invention, the titanium alloy wire is a titanium alloy wire treated with ethanol with a concentration of 50 - 95%. After treatment with ethanol, the impurity elements on the surface of the titanium alloy can be removed, the influence of the impurity elements on the interfacial bonding strength can be reduced, and the mechanical properties of the magnesium-based composite material can be improved.

[0036] In some embodiments of the present invention, the pressure for pressing into shape is 100 - 180 MPa; in some embodiments of the present invention, the pressure for pressing into shape is any value of 100 MPa, 105 MPa, 110 MPa, 115 MPa, 120 MPa, 125 MPa, 130 MPa, 135 MPa, 140 MPa, 145 MPa, 150 MPa, 155 MPa, 160 MPa, 165 MPa, 170 MPa, 175 MPa, 180 MPa or any range value formed by any two of them.

[0037] In some embodiments of the present invention, the pressure increase rate of the press molding is 1-10 MPa / s; in some embodiments of the present invention, the pressure increase rate of the press molding is any value among 1 MPa / s, 2 MPa / s, 3 MPa / s, 4 MPa / s, 5 MPa / s, 6 MPa / s, 7 MPa / s, 8 MPa / s, 9 MPa / s, 10 MPa / s or the range value formed by any two of them.

[0038] In some embodiments of the present invention, the pressure holding time of the press molding is 1-30 min; in some embodiments of the present invention, the pressure holding time of the press molding is any value among 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, 30 min or the range value formed by any two of them.

[0039] In some embodiments of the present invention, the press molding is carried out by vertical cold pressing.

[0040] The purpose of pressing the composite material blank in the present invention is to increase the density of the magnesium-based composite material, reduce the sintering temperature, increase the interfacial bonding strength, discharge air to reduce sintering closed pores, and control the sintering shape.

[0041] In some embodiments of the present invention, the frequency of the vibration is 25-100 HZ; in some embodiments of the present invention, the frequency of the vibration is any value among 25 HZ, 27 HZ, 30 HZ, 32 HZ, 35 HZ, 37 HZ, 40 HZ, 42 HZ, 45 HZ, 47 HZ, 50 HZ, 52 HZ, 55 HZ, 57 HZ, 60 HZ, 62 HZ, 65 HZ, 67 HZ, 70 HZ, 72 HZ, 75 HZ, 77 HZ, 80 HZ, 82 HZ, 85 HZ, 87 HZ, 90 HZ, 92 HZ, 95 HZ, 97 HZ, 100 HZ or the range value formed by any two of them. The purpose of vibrating the mold is to improve the density of the magnesium alloy powder filling, exhaust air, and reduce sintering defects.

[0042] In some embodiments of the present invention, the direction of the vibration is the vertical direction.

[0043] In some embodiments of the present invention, the step of sintering the composite material blank is: putting the composite material blank into a sintering furnace, evacuating 1-5 times and then filling with an inert gas for sintering.

[0044] In some embodiments of the present invention, the step of evacuating the air is as follows: evacuate the air until the vacuum degree ≤ 2×10 -3 MPa and then stop, fill with an inert gas to normal pressure, and then continue to evacuate the air, and perform the vacuum treatment repeatedly for 1 to 5 times.

[0045] In some embodiments of the present invention, the pressure for sintering is 500 to 1000 Pa; in some embodiments of the present invention, the pressure for sintering is any value among 500 Pa, 550 Pa, 600 Pa, 650 Pa, 700 Pa, 750 Pa, 800 Pa, 850 Pa, 900 Pa, 950 Pa, 1000 Pa or the range value formed by any two of them. In the sintering step of the present invention, an inert gas is filled so that the pressure of the inert gas reaches 500 to 1000 Pa, and sintering is performed under this pressure.

[0046] In some embodiments of the present invention, the atmosphere for sintering is an inert atmosphere.

[0047] In some embodiments of the present invention, for sintering, first heat up to 780 to 850 °C and keep it warm for 0.5 to 1 h, and then cool down to 730 to 770 °C and keep it warm for 1.5 to 2 h. In the present invention, sintering is first performed at 780 to 850 °C mainly to completely liquefy the magnesium alloy, and at the same time control the temperature threshold for forming the TiAl3 interface compound at the interface, so as to promote the formation of the interface compound TiAl3 at the interface; then sintering is performed at 730 to 770 °C to inhibit the volatilization of the magnesium alloy, reduce the formation of magnesium vapor, and at the same time this temperature is the reasonable annealing temperature of the titanium alloy, which can improve the strength of the prepared magnesium-based composite material.

[0048] In the present invention, by controlling the sintering temperature, sintering process and sintering atmosphere during sintering, the interface strength and density of the composite material after sintering are improved, thereby significantly improving the strength of the magnesium-based composite material. The strength of the framework-reinforced magnesium-based composite material is mainly determined by the framework material, and a stronger framework material will lead to a significant improvement in the performance of the prepared framework-reinforced magnesium-based composite material.

[0049] In some embodiments of the present invention, the temperature for heating up is 780 to 850 °C. For example, it can be selected from any value among 780 °C, 790 °C, 800 °C, 810 °C, 820 °C, 830 °C, 840 °C, 850 °C or the range value formed by any two of them.

[0050] In some embodiments of the present invention, the temperature for cooling down is 730 to 770 °C. For example, it can be selected from any value among 730 °C, 735 °C, 740 °C, 745 °C, 750 °C, 755 °C, 760 °C, 765 °C, 770 °C or the range value formed by any two of them.

[0051] In some embodiments of the present invention, the heating rate of sintering is 5-15 °C / min; in some embodiments of the present invention, the heating rate of sintering is any value among 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min, 10 °C / min, 11 °C / min, 12 °C / min, 13 °C / min, 14 °C / min, 15 °C / min or the range value formed by any two of them.

[0052] In some embodiments of the present invention, the method for preparing the magnesium-based composite material includes the following steps:

[0053] Arrange and fix the titanium alloy wire in a mold to obtain a titanium alloy frame;

[0054] Then inject magnesium alloy into the titanium alloy frame, vibrate in the vertical direction at a vibration frequency of 25-100 HZ, and then raise the pressure to 100-180 MPa at a pressure increase rate of 1-5 MPa / s and press for 3-10 min to obtain a composite material blank;

[0055] Put the composite material blank into a sintering furnace, evacuate to make the vacuum degree ≤ 2*10 -3 MPa and stop, fill with inert gas to normal pressure, evacuate repeatedly 1-5 times, and then fill with inert gas to a pressure of 500-1000 Pa. First, heat up at a heating rate of 5-15 °C / min to 780-850 °C and keep warm for 0.5-1 h, then cool down to 730-770 °C and keep warm for 1.5-2 h, and cool naturally to obtain the magnesium-based composite material.

[0056] The repeated evacuation in the present invention is to reduce the oxygen content in the sintering environment and reduce oxidation. The 500-1000 Pa inert gas environment is to inhibit the volatilization behavior during the sintering of magnesium alloy and increase the material yield. The design of the heating temperature and the holding time after heating is to increase the interfacial bonding strength and density, and the cooling temperature and the holding time after cooling are for the heat treatment of the titanium alloy frame with the furnace to improve the strength of the prepared magnesium-based composite material.

[0057] The third aspect of the present invention provides the application of the magnesium-based composite material described in the first aspect of the present invention in the fields of transportation equipment, ocean engineering equipment, building materials or electronic equipment.

[0058] The beneficial effects of the present invention are as follows: The magnesium-based composite material in the present invention is reinforced with a titanium alloy frame, and the titanium alloy frame and the magnesium alloy have a good bonding interface, so that the prepared magnesium-based composite material has high mechanical properties and low density. Specifically: the yield strength ≥ 500 MPa, the tensile strength ≥ 500 MPa, the elastic modulus ≥ 80 GPa, and the density ≤ 3.2 g / cm3 , significantly solving the problem of poor strength of existing magnesium alloys.

[0059] In the preparation method of the present invention, by constructing a titanium alloy framework, then filling magnesium alloy powder into the titanium alloy framework, and then controlling the sintering parameters, a magnesium-based composite material with high strength, low density and high density is prepared. The preparation method has a simple process, is easy to operate, has low requirements for equipment, and is suitable for large-scale industrial production. Description of the Drawings

[0060] Figure 1 It is a schematic structural diagram of the mold used in the embodiment of the present invention.

[0061] Figure 2 It is a SEM image of the magnesium-based composite material obtained in Example 1.

[0062] Figure 3 It is a SEM image of the fracture of the magnesium-based composite material obtained in Example 1.

[0063] Figure 4 It is a high-magnification scanning electron microscope image of a partial position of the fracture of the magnesium-based composite material obtained in Example 1.

[0064] Figure 5 It is a stress-strain curve of the magnesium-based composite materials obtained in Example 1 and Example 2.

[0065] Figure 6 It is a stress-strain curve of the magnesium-based composite materials obtained in Example 1 and Comparative Example 1. Detailed Embodiments

[0066] The following further details the specific implementation of the present invention in conjunction with the drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that for the following processes that are not particularly detailed, those skilled in the art can refer to the prior art to implement or understand. The reagents or instruments used without indicating the manufacturer can be obtained as conventional products through commercial purchase.

[0067] As Figure 1 shown in the structural schematic diagram, the internal dimensions of the mold used in the following examples are: 300mm * 200mm * 100mm. There is a uniformly arranged through-hole array on the mold. The aperture of the through-hole is: 3.5mm, and the hole pitch is: 5mm. A feeding hole is provided on the top surface of the mold, and the aperture of the feeding hole is: 50mm.

[0068] Example 1

[0069] This example provides a preparation method for a high-strength and tough TC4 wire-frame reinforced magnesium-based composite material, which specifically includes the following steps:

[0070] 1. Material preparation: The composite material uses TC4 wires with a purity ≥ 99.99% and a diameter of 3.0 mm, and spherical AZ91 powder with a purity ≥ 99.99% and a particle size of 100 μm.

[0071] Prepare raw materials according to the volume percentage of TC4 wires being 45% and the volume percentage of spherical AZ91 powder being 55%;

[0072] 2. Surface treatment: Immerse the TC4 wires in a 95% ethanol solution for 10 min to remove surface impurity elements, then wash and dry.

[0073] 3. Loading: Insert the dried TC4 wires into Figure 1 the through-hole array of the mold in and fix them in the mold. Add spherical AZ91 powder through the feeding hole of the mold, and maintain vertical vibration of the mold at a frequency of 100 Hz. Then perform pressing: Use vertical cold pressing to press the loaded mold, with a pressure of 150 MPa, a pressure increasing rate of 5 MPa / s, and a pressure holding time of 3 min. After cold pressing, a TC4 / AZ91 composite material blank with dimensions of 300 mm * 200 mm * 85 mm is obtained.

[0074] 4. Sintering: Load the pressed TC4 / AZ91 composite material blank into a high-vacuum sintering furnace, evacuate to a vacuum degree ≤ 2 * 10 -3 MPa and stop, fill with argon to atmospheric pressure, perform vacuum treatment 3 times repeatedly, fill with argon again to a pressure of 500 Pa, heat up to 800 °C at a heating rate of 10 °C / min, hold for 0.5 h, cool down to 750 °C, hold for 1.5 h, and then cool with the furnace to room temperature to obtain the high-strength and tough TC4 wire-frame reinforced magnesium-based composite material in this example.

[0075] Example 2

[0076] This example provides a preparation method for a high-strength and tough TC4 wire-frame reinforced magnesium-based composite material, which specifically includes the following steps:

[0077] 1. Material preparation: The composite material uses TC4 wires with a purity ≥ 99.99% and a diameter of 3.5 mm, and spherical AZ91 powder with a purity ≥ 99.99% and a particle size of 100 μm.

[0078] Prepare raw materials according to the volume percentage of TC4 wires being 50% and the volume percentage of spherical AZ91 powder being 50%;

[0079] 2. Surface treatment: Immerse the TC4 wires in a 95% ethanol solution for 10 min to remove surface impurity elements, then wash and dry.

[0080] 3. Loading: Insert the dried TC4 wires into Figure 1The through-hole array of the mold therein is then fixed in the mold. Spherical AZ91 powder is added through the feeding hole on the mold, and vertical vibration of the mold at a frequency of 100 HZ is maintained. Then, pressing is carried out: vertical cold pressing is used to press the loaded mold, with a pressure of 180 MPa, a pressure increasing rate of 5 MPa / s, and a pressure holding time of 6 min. After cold pressing, a TC4 / AZ91 composite billet with dimensions of 300 mm * 200 mm * 95 mm is obtained.

[0081] 4. Sintering: The pressed TC4 / AZ91 composite billet is loaded into a high-vacuum sintering furnace. The vacuum is pumped until the vacuum degree ≤ 2 * 10 -3 MPa and then stopped. Argon is filled until normal pressure is reached. The vacuum treatment is repeated 3 times. Argon is filled again until the pressure is 500 Pa. The temperature is raised to 820 °C at a heating rate of 10 °C / min, held for 0.5 h, cooled to 750 °C, held for 2 h, and then cooled to room temperature with the furnace to obtain the high-strength and tough TC4 wire-frame reinforced magnesium matrix composite material in this example.

[0082] Comparative Example 1

[0083] This example provides a preparation method of a TC4-frame reinforced magnesium matrix composite material, which specifically includes the following steps:

[0084] 1. Preparation of a porous TC4 preform: TC4 powder is loaded into a mold. After applying a pressure of 12 MPa to compact the TC4 powder, the compacted TC4 powder together with the mold is placed in a vacuum-sealed container for vacuum sintering. After the sintering temperature is raised from room temperature to 1300 °C, it is held at 1300 °C for 2 h and then cooled to room temperature to obtain a porous TC4 preform;

[0085] 2. Magnesium alloy infiltration: AZ91 magnesium alloy is melted into a magnesium alloy melt under a protective atmosphere and heated to 720 °C for holding. The magnesium alloy melt is infiltrated into the porous TC4 preform and air-cooled to room temperature to obtain the TC4-frame reinforced magnesium matrix composite material in this example.

[0086] The TC4-frame reinforced magnesium matrix composite material in this example includes the following raw materials by volume percentage: the volume percentage of TC4 powder is 45%, and the volume percentage of spherical AZ91 powder is 55%.

[0087] Comparative Example 2

[0088] This example provides a preparation method of a cast TC4 particle-reinforced magnesium matrix composite material, which specifically includes the following steps:

[0089] Mix spherical TC4 particles with a particle size of 50 μm and spherical AZ91 particles with a particle size of 100 μm evenly under the protection of an inert atmosphere. Subsequently, add the evenly mixed powder into a crucible and heat it to 720 °C. Extend the stirring paddle to an appropriate position below the melt surface, start the stirring paddle, with a stirring speed of 1000 r / min, stir evenly for 20 min, then cool down to 690 °C, stop stirring, and then start ultrasonic treatment. The ultrasonic frequency is 30 kHz, and the duration is 20 min. Subsequently, let the mixed melt stand for 20 min. Finally, quickly place the crucible containing the melt into a water-cooling system for cooling. This water-cooling system uses circulating water cooling, and a as-cast magnesium matrix composite reinforced with TC4 particles can be obtained.

[0090] The as-cast magnesium matrix composite reinforced with TC4 particles in this example includes the following raw materials by volume percentage: the volume percentage of TC4 powder is 45%, and the volume percentage of spherical AZ91 powder is 55%.

[0091] Performance testing

[0092] Use a scanning electron microscope to test the surface morphology of the magnesium matrix composite prepared in Example 1, specifically as Figure 2 shown, and then test the surface morphology at the fracture position of the magnesium matrix composite prepared in Example 1, specifically as Figure 3 shown. Then use a high-magnification scanning electron microscope to test the surface morphology at a local position of the fracture of the magnesium matrix composite prepared in Example 1, specifically as Figure 4 shown. From Figures 2 to 3 it can be seen that the TC4 wire frame in the magnesium matrix composite prepared in Example 1 has a complete morphology, and a serrated interface structure can be clearly observed at the joint. The formation of the interface structure helps to improve the strength and elongation of the magnesium matrix composite. From Figure 4 it can be seen that tearing-type fracture lines can be observed at the magnified fracture position of the magnesium matrix composite prepared in Example 1, which also proves the excellent combination of TC4 and the magnesium alloy interface. In addition, the implantation of the TC4 wire frame better hinders the propagation of cracks during the deformation process of the magnesium matrix composite and enhances the toughness of the magnesium matrix composite.

[0093] Respectively test the yield strength, tensile strength, elongation, and elastic modulus of the magnesium matrix composites obtained in Examples 1-2 and Comparative Examples 1-2. The stress-strain curves obtained during the test are specifically as Figure 5 and Figure 6 shown, and the specific test results are shown in Table 1 below.

[0094] Table 1 Mechanical property data of the magnesium matrix composites obtained in Examples 1-2 and Comparative Examples 1-2

[0095]

[0096] As can be seen from Table 1, compared with Comparative Examples 1-2, the mechanical properties of the magnesium-based composites obtained by the preparation methods in Examples 1-2 of the present invention are significantly improved. Specifically, the yield strength is 512-525 MPa, the tensile strength is 549-571 MPa, the elongation is 4.9-5.7%, and the elastic modulus exceeds 80 GPa. The reason for the performance improvement of the magnesium-based composites in Examples 1-2 may be that the TC4 wire frames are evenly distributed inside the magnesium-based composites and, as the reinforcing phase, bear the external force applied during material deformation. Moreover, the tight bonding between the TC4 wire frames and the matrix interface contributes to the conduction and bearing of stress during deformation. Comparative Example 1 uses a process of sintering to prepare a titanium alloy frame and then infiltration. There will be closed pore defects during the infiltration process, resulting in poor strength. In addition, the environmental influencing factors during the infiltration process are huge, and oxidation and temperature control are both difficult problems. Therefore, there are high requirements for the preparation equipment and environment. The present invention uses TC4 wires arranged and fixed in a mold as the frame, avoiding the defect of unstable strength during the frame sintering process. On the basis of ensuring the frame strength, a method of directly sintering the magnesium alloy powder filled in the frame is adopted. By controlling the environmental parameters (temperature, oxygen content, atmosphere pressure, holding time, etc.) in a high-vacuum sintering furnace, the formation of composite material defects is effectively avoided, thereby obtaining excellent strength.

[0097] In addition, compared with Examples 1-2, the reason for the density reduction of the magnesium-based composites in Comparative Examples 1-2 is that there are defects and pores inside the prepared magnesium-based composites, resulting in a decrease in the density.

[0098] From Figure 5 and Figure 6 it can be seen that the high-strength and tough TC4 wire frame-reinforced magnesium-based composites prepared in Examples 1-2 of the present invention have significantly higher mechanical properties than Comparative Example 1. While having ultra-high tensile properties, they also have good elastic modulus. A better elastic modulus means better adaptability in future engineering application scenarios. By comparing Example 1 and Example 2, it can be seen that as the volume percentage of TC4 wire increases, the mechanical properties of the prepared magnesium-based composites also increase significantly.

[0099] The above has described the embodiments of the present invention in detail. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the purpose of the present invention. In addition, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

Claims

1. A magnesium-based composite material, characterized in that: The preparation material comprises the following volume percentages: 45-50% of titanium alloy frame; 50-55% of magnesium alloy; the titanium alloy frame is composed of at least two titanium alloy wires arranged in an array.

2. The magnesium-based composite material according to claim 1, characterized in that: The titanium alloy wire has at least one of the following characteristics: (a1) The distance between two adjacent titanium alloy wires is 0.75 mm to 5 mm; (a2) the diameter of the titanium alloy wire is 0.5 mm to 3.5 mm; (a3) The material of the titanium alloy wire is selected from at least one of TC4, TC6, TC11, Ti1023, TA12, TA7, and TA11.

3. The magnesium-based composite material according to claim 1, characterized in that: The magnesium alloy includes at least one of Mg-Al alloy, Mg-Zn alloy, Mg-Mn alloy and Mg-RE alloy.

4. The magnesium-based composite material according to claim 1, characterized in that: The particle size of the magnesium alloy is 10 to 100 μm.

5. The method for preparing the magnesium-based composite material according to any one of claims 1 to 4, characterized in that: The following steps are involved: Arranging and fixing the titanium alloy wires in a mold to obtain a titanium alloy frame; Then, magnesium alloy is injected into the titanium alloy frame, and the frame is pressed and formed after vibration to obtain a composite material blank; The composite material green body is sintered to obtain the magnesium-based composite material.

6. The method for preparing the magnesium-based composite material according to claim 5, characterized in that: The compression molding has at least one of the following characteristics: (b1) the pressure of the compression molding is 100 to 180 MPa; (b2) the pressure increase rate of the compression molding is 1 to 10 MPa / s; (b3) The holding time of the compression molding is 1 to 30 minutes.

7. The method for preparing the magnesium-based composite material according to claim 5, characterized in that: The frequency of the vibration is 25-100 Hz; and / or the direction of the vibration is vertical.

8. The method for preparing the magnesium-based composite material according to claim 5, characterized in that: The step of sintering the composite material green body is as follows: placing the composite material green body in a sintering furnace, evacuating the furnace for 1 to 5 times, and then filling the furnace with inert gas for sintering.

9. The method for preparing the magnesium-based composite material according to claim 5 or 8, characterized in that: The sintering has at least one of the following characteristics: (c1) the sintering pressure is 500-1000 Pa; (c2) the sintering atmosphere is an inert atmosphere; (c3) The sintering is first heated to 780-850°C and kept at this temperature for 0.5-1h, and then cooled to 730-770°C and kept at this temperature for 1.5-2h; (c4) The heating rate of the sintering is 5-15°C / min.

10. Use of the magnesium-based composite material according to any one of claims 1 to 4 in the fields of transportation equipment, marine engineering equipment, building materials or electronic equipment.

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